FUEL
·
2018
·
IF 4.908
Haiyang Tian,Hongping Quan,Zhiyu Huang,Silong Jiang
The non-hydrophobically associating water-soluble polymer (DPAM) of acrylamide (AM) and dimethylamino propyl methacrylamide (DMAPMA) was synthesized. Then pH-switchable and CO 2 ‑switchable viscoelastic liquids based on DPAM and anionic surfactant sodium dodecyl sulfate (SDS)(referred to as DPAM-SDS) were developed. When minor HCl aqueous solution was added into the DPAM and SDS aqueous mixture or CO 2 was bubbled into it, the tertiary amine groups of DPAM were protonated to form quaternary ammonium groups, some of which in the same quaternary ammonium groups of DPAM “bridged” some SDS through noncovalent electrostatic attraction, behaving like a pseudo-hydrophobically associating water-soluble polymer and forming viscoelastic fluids as checked through environmental scanning electron microscope(ESEM) and rheology. Upon removing of CO 2 or back of pH by minor NaOH aqueous solution, the quaternary ammonium species of DPAM were deprotonated back to tertiary amine groups, separating the pseudo-hydrophobically associating water-soluble polymer back to DPAM and SDS molecules, which resulted in forming low-viscosity water solution. The switchable viscoelastic conversion can be repeated.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2021
·
IF 9.297
Xiaojiang Li,Li Wang,Hongsheng Lu,Na Wang,Baogang Wang,Zhiyu Huang
Surfactant extraction is the common method for treating oil sands. However, the recovery of traditional surfactant is difficult, and the oil emulsification phenomenon and generation of tailings are also caused easily. To develop the cleaner and sustainable approach for treating oil sands, a switchable water N, N, N′, N′ -tetramethylhexanediamine (TMHDA) was used to improve extraction by surfactant sodium dodecyl benzene sulfonate (SDBS) solution with low concentration. Here, the TMHDA-containing SDBS solution has CO 2 switchability because of the electrostatic interaction between SDBS solution and TMHDA with CO 2 response, and can be also emulsify reversibly n-heptane, diesel oil, even crude oil, providing the possibility for separating oil from oil sands. The effective extraction of oil sands is performed by 1 mM (less than critical micelle concentration (CMC)) SDBS solution combined with TMHDA, which was also demonstrated by thermogravimetric analyzer, scanning electron microscope and elemental analysis. The residual oil content of oil sands is reduced to 0.515 wt% and 90.8% oil is removed by adding 0.15 g/mL TMHDA. Interestingly, oil is separated and fine sands is separated by introducing CO 2 , and the TMHDA-containing SDBS is recycled upon N 2 /65 °C.According to the detection of interfacial tension and Fourier Transform Infrared Spectroscopy (FTIR), it is demonstrated that the improved oil removal is ascribed to the adsorption of SDBS on solid surface and the reduced oil-water interface tension by the addition of TMHDA. Based on the evaluation of economic and environmental value, this sustainable approach exhibits potential application for treating oil sands in practical industry.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
Guanghui Zhang,Yan Liu,Chao Chen,Lulu Long,Jinsong He,Dong Tian,Ling Luo,Gang Yang,Xiaohong Zhang,Yanzong Zhang
Superwettability materials with a single function cannot meet the needs of different oil-bearing wastewater separations. This study proposed a preparation method for the swappable superwettability on cotton fabrics. The superhydrophobic fabric surface that was wetted with ethanol transformed from being superhydrophobic/superoleophilic to being superhydrophilic/underwater superoleophobic, and returned to superhydrophobicity after drying. Regardless of whether it is the oil removal process or the water removal process, the flux of the fabric was above 15,300 L·m −2 h −1 , and the separation efficiency was over 98.6%. Although the continuous separation was conducted 50 times, the flux and separation efficiency did not change significantly. The prepared material could exhibit superhydrophobicity after being immersed in solutions of different pH and actual seawater for some time, even after 50 times of sand impact experiments, indicating excellent mechanical durability and chemical stability. Thus, the preparation strategy of the swappable superwettability materials can develop oil–water separation technology.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2021
·
IF 3.605
Xin Lv,Xiaojiang Li,Yang Ge,Qingping Li,Hongsheng Lu
In this work, the approach for separating paraffin wax is proposed by using Span 80 combined with switchable water N,N,N′,N′-tetramethyl-1,6-hexanediamine (TMHDA), where the emulsification of paraffin wax can be promoted and paraffin wax is also separated sustainably. Here, the Span 80-containing mixture system exhibits an enhanced emulsification ability and CO2-switchable behavior upon the addition of TMHDA. Then, the paraffin wax is effectively emulsified by this switchable system containing Span 80 and TMHDA. Based on the detection of water separation rate, rheological behavior, and micrographs of emulsified paraffin wax, it is found that the emulsification of paraffin wax can be improved by increasing the paraffin wax content and Span 80 content, and the viscosity of the paraffin wax is reduced after emulsification by this switchable system, which ascribes to the dispersion of wax crystals. In addition, the paraffin wax is separated upon introducing CO2, and the TMHDA solution is recovered upon treating with N2 at 65 °C after separating the paraffin wax. The sustainable separation of paraffin wax results from the aggregation of wax crystals because of the reduced obstruction of oil droplets for wax crystals caused by the high ionic strength and the reduced surface activity of this system upon introducing CO2. Herein, it is expected that this sustainable separation can be applied in deposited wax removal in pipelines of crude oil transport.
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
Membranes
·
2022
·Vol. 13
·期 1
·14
·
IF 4.562
Jingjun Peng,Bhaskar Jyoti Deka,Shaodi Wu,Zhongyuan Luo,Jehad A. Kharraz,Wei Jia
Water pollution caused by oil spills or sewage discharges has become a serious ecological environmental issue. Despite the membrane separation technique having a promising application in wastewater purification, the membrane fabrication method and separation robustness have remained unsatisfactory until now. Herein, we developed a novel strategy, spacer-assisted sequential phase conversion, to create a patterned polyvinylidene fluoride@polypropylene (P-PVDF@PP) substrate membrane with a multiscale roughened surface. Based on that surface structure, the underwater oil resistance behavior of the P-PVDF@PP membrane was improved. Moreover, owing to the abundant active sites on the P-PVDF@PP surface, the polydopamine/P-PVDF@PP (PDA/P-PVDF@PP) Janus membrane could be readily fabricated via wet chemical modification, which exhibited excellent switchable oil–water separation performance. Regarding surfactant-stabilized oil-water emulsion, the as-prepared PDA/P-PVDF@PP Janus membrane also had robust separation efficiency (as high as 99% in the n-hexane/water, chloroform/water, and toluene/water emulsion separation cases) and desirable reusability. Finally, the underlying mechanism of emulsion separation in the PDA/P-PVDF@PP Janus membrane was specified. The as-designed PDA/P-PVDF@PP Janus membrane with high-efficiency oil–water separation shows potential application in oily wastewater treatment, and the developed fabrication method has implications for the fabrication of advanced separation membranes.Keywords:emulsion separation;Janus membrane;patterned interface;switchable wettability
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBON
·
2019
·
IF 7.466
Yuheng Xu,Zedong Zhang,Xiangfei Geng,Jing Jin,Muzaffar Iqbal,Aijuan Han,Bin Ding,Junfeng Liu
The adsorption and recovery of crude-oil from oily water using oil-selective adsorbents is a highly promising solution for the increasing worldwide oil pollution, but remain a challenge. Herein, we reported a carbon foam (CF) with switchable wettability as smart materials for fast oil adsorption and recovery. By grafting poly(4-vinylpyridine) (P4VP) onto the surface of CF, the obtained smart foam presented a pH responsiveness and could change superhydrophilic and superhydrophobic surface according to the pH value. Thus, the smart responsive carbon foam could fast adsorb the oil in neutral solution (pH = 7) with high oil adsorption capacity of 62–120 g g −1 and desorb all the adsorbed oil in acidic solution (pH = 1) within 1.5 min. In addition, only 3% loss was observed for oil (chloroform) adsorption and recovery after successive reuses of up to 15 cycles, which demonstrated great recyclability of the materials.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Extreme Mechanics Letters
·
2021
·
IF 4.567
Qi Li,Ping Zhang,Canhui Yang,Huiling Duan,Wei Hong
On-demand adhere to and detach from soft and wet surfaces are crucial for hydrogels for applications in tissue engineering , soft machines, and soft robotics. Whereas strong adhesion has been achieved between hydrogels, on-demand switching from strong adhesion to weak adhesion for benign detachment is still under explorations. Herein, we report an approach for switchable adhesion between hydrogels by invoking a mechanical process, wrinkling. The approach is demonstrated by bonding two hydrogel adherends with a wrinkled hydrogel adhesive , with the formation and characterizations of wrinkles tailored by regulating the prestretch of adherend and optimizing the ingredients of adhesive synergistically. On one hand, the formation of wrinkles enhances adhesion by creating a tortuous path for crack propagation and an extended energy dissipation zone. The resulting adhesion is robust to elicit bulk dissipation within the adherend and transform the once adhesive failure to cohesive failure . On the other hand, the suppression of wrinkles deactivates the adhesion enhancement mechanism to facilitate effortless debonding. As a proof-of-concept, a hydrogel patch that can strongly adhere to a damaged hydrogel device for repair and gently detach after repairing, based on the switchable hydrogel adhesion, is demonstrated. The proposed method expands the design space for hydrogel adhesion.
研究领域:
生物医学工程
·
材料科学
·
组织工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 12
·4300-4306
·
IF 7.393
Yanmin Zhao,Xin Geng,Xinxin Shi,Yifei Guo,Yuanqiang Sun,Lingbo Qu,Zhaohui Li
Developing optical oxygen-sensitive nanoparticles with good biocompatibility and low cost to rapidly detect molecular oxygen in a signal turn-on mode is highly desirable. Herein, we present a phenylenediamine-derived carbon dot (CD), which has been found to display a fluorescence-switchable property, with fluorescence quenching by Na2S2O4 and fluorescence recovery triggered by O2. Because of this unique property, we directly employed the quenched CDs as a reversible probe for the fluorescence turn-on detection of molecular oxygen and found that this detection mode possessed a short response time of 12 s and high sensitivity. Moreover, this CD solution could be used as a writeable ink for the patterning of paper strips and security service without any loss in the fluorescence-switchable property. We thus achieved CD-based test strips for oxygen detection in vacuum packaging. This study not only provides a convenient, low-cost and practical way for oxygen detection but also reveals a fluorescence-switchable CD that will find its applications in numerous O2-involved fields.
研究领域:
化学
·
生物传感
·
材料科学
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Zhongqi Ren,Hui Yu,Xiaojia Wu,Weidong Liu,Fan Zhang,Shichao Tian,Zhiyong Zhou
The separation of aromatics and aliphatic hydrocarbons is one of the most challenging and energy consuming operations in the petrochemical industry. In this work, two switchable solvents, 1,8-diazabicyclo[5.4.0]undec-7-ene imidazole ([DBU][Im]) and 1,1,3,3-tetramethylguanidine imidazole ([TMG][Im]), were synthesized and used for phase-change separation of toluene from n-heptane. The structures of these two switchable solvents were analyzed by 1 H Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FT-IR) spectroscopy. The miscibility of various components in these two ILs before and after treatment with CO 2 were studied, the results of which indicated that both these two switchable solvents could be utilized to achieve the effective separation of toluene from n-heptane. Among them, [TMG][Im] was preferable to be used at a low toluene content in the initial toluene/n-heptane system through feasibility study. The effects of extraction time, switchable solvent dosage and molar fraction of toluene on separation performance and the reusability were also investigated, demonstrating that [TMG][Im] could be used simply and feasibly for phase-change separating toluene from n-heptane and showed very good reusability and stability. Finally, the mechanism of reversible phase-change extraction process with [TMG][Im] was explored, indicating that the formation of [TMG][ImCO 2 ] could greatly increase the polarity of the switchable solvent, which is conducive to separating toluene and recovering [TMG][Im] by removing CO 2 .
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2023
·
IF 11.1
Jie Qi,Yang Ge,Qingping Li,Xin Lv,Xiaojiang Li,Na Wang,Hongsheng Lu
Paraffin wax has caused obvious detrimental consequences to the extraction for fossil fuels, and posed environmental challenge due to the absence of cleaner methods for paraffin wax removal. A cleaner and sustainable approach for paraffin wax removal was developed using the switchable polarity solvents (SPS). Three SPS with low polarity, including dipropylamine (DPA), ethylbutylamine (EBA), and dibutylamine (DNBA) were selected for paraffin wax removal. Compared with bubbling CO 2 into SPS straightway, the transformation of the polarity quantified by normalized polarity energy confirms the addition of water is benefit to enlarge the polarity scope. Paraffin wax is removed at the initial state and separated at the final state by CO 2 -induced polarity transformation of SPS. The dissolution rates for paraffin wax of DPA and EBA reached 0.071 g/min and 0.062 g/min, which surpassed that of traditional solvents, such as o-xylene (0.045 g/min) and Petroleum ether (0.017 g/min), indicating that these selected SPS is suitable for paraffin wax removal. The paraffin wax dissolution behaviors of SPS can be accurately matched using modified Apelblat models with root-mean-square deviation of 1.085%. With the addition of water, more than 99% of paraffin wax is separated from DPA and EBA by introducing CO 2 within 10mins, which is a better alternative method for energy-intensive distillation process . The introduction of water is indispensable for improving the separation efficiency, since it enlarged the polarity difference between solvents and paraffin wax. The thermal behavior of separated paraffin wax detected by Differential Scanning Calorimetry remained steady, and there were negligible residual solvents detected indicate the feasible separation of paraffin wax. Both SPS and water are recovered upon N 2 /80 °C, which retain good recyclability for paraffin wax removal. These findings confirms the applicability of SPS in the sustainable and cleaner removal of paraffin wax. The use of SPS provides an alternative and promising approach for paraffin wax removal for ensuring the demands of low-energy consumption and environment.
研究领域:
能源与环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Benoit Rugabirwa,David Murindababisha,Yin Li,Yanzhen Hong,Yuzhong Su,Hongtao Wang,Jun Li
We propose a novel and cyclic synthetic approach for controlling crystal polymorphs of CaCO3 by using green CO2-responsive switchable solvents which acted as both the CO2 capturer for the carbonate source and the polymorphisms director. Five solvents were employed, and various reaction conditions such as calcium resources, calcium concentration, reaction temperature, and reaction time were investigated. Results show that this developed framework permits producing any crystalline CaCO3 phases including metastable vaterite and aragonite in pure phases by selecting a suitable solvent and adjustment of the reaction conditions. Furtherly, the mechanism study demonstrates that the solvents attach on the surface of the primary nanoparticles to selectively control and direct the growth of any specific polymorph phases. Eventually, the nuclei are self-assembled into an oriented geometry, allowing the growth and stability of specific crystals; as such, spherical vaterite, rods, and shuttle-like aragonite crystals can be obtained. This new configuration would be an appropriate and an efficient method to apply to large-scale production, therefore, a promising process attributed to complete solvent recovery and regeneration of the initial reactants, thus being an environmentally risk-free route.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
POLYMER
·
2021
·
IF 4.43
Shan Lu,Jinling Li,Fei Liu,Meiling Chen,Haining Na,Jin Zhu
Modification of cellulose homogeneously by graft copolymerization via grafting-from or grafting-to approaches is an attractive and versatile way to impart specific properties onto this promising renewable material. The grafting efficiency is greatly influenced by the solvent and catalyst used during this process. In this study, cellulose- graft -poly ( l -lactic acid) (C- g -PLLA) was prepared by ring opening polymerization of l -lactide (LA) (grafting-from) and transesterification of PLLA (grafting-to) with cellulose dissolved in CO 2 switchable solvent. The impact of the presence of 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) was then elucidated by comparing the grafting efficiency of the process with or without adding extra amount of this organic superbase . Results showed that without adding extra DBU, the grafting efficiency increased with an increase in concentration of grafting agents (LA or PLLA). However, when extra DBU was added, the grafting efficiency decreased with increased levels of DBU. These results indicate that the DBU protonated by the hydroxyl group from cellulose participated in the dissolution of cellulose after capture of CO 2 in the switchable solvent, and played a role in the graft copolymerization to produce C- g -PLLA. On the other hand, the free DBU that was unprotonated displayed an antagonistic effect towards grafting copolymerization . Detailed graft copolymerization pathways and related modes of action were then considered in attempt to provide new insight into the role of CO 2 switchable solvent for cellulose modification by ROP or transesterification .
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）